When discussing FLR, WLM, Femdom, Chastity, or any type of D/s, you'll find the warning "be careful what you wish for, you just might get it." Sarah at the Male Chastity Blog has posted about it, Vanessa Chaland mentioned it in a comment to the last post (though I took her comment in the vein she meant it - something lighthearted and playful), the "Being Her Knight" blog discusses it, and there are many many other examples out there.
The warning exists because there are so many men who enter this arena without thinking about the consequences. They generally want to get their rocks off and they're only thinking with that head. They want to play a game, have a little kink, and control the entire thing from the bottom, as it were.
The warning in my case will never apply and, even on a general scale, I don't think it actually ever applies. The warning presumes that the woman just might take the whole thing farther than the man ever intended or even wanted. The warning is unrealistic because the number of times in which the wife goes from a non-player to one who goes well beyond the limits of the man is extremely small.
From my observations of people, extreme changes in behavior and desires throughout life is very rare. I'm old enough to have known a lot of people for a long period of time. The core of these people haven't changed. Yes, they have grown, matured, and changed. But none have had extreme personality changes. My friend's wife hasn't gone from being milquetoast to a biker chick. She has becomes slightly less uptight, but she's still uptight. None of my wild friends have become suburban, stay at home moms.
True, people do and can change. But for the most part, their personality is their personality throughout their lives. And from what I've seen, sometimes the opposite actually occurs. The person who is cheap in his 30's only becomes more cheap as the years pass. The person who is risk averse becomes more and more risk averse as the person gets older.
Getting to sex, unless there is some drastic life changing event (like divorce - I have seen many divorced people drastically change their behavior), the person's sexual preference generally stays the same. If there is someone who is not kinky by 25, 30, or 40, they usually don't all of a sudden start getting seriously kinky. If the wife refuses to give her husband blowjobs in her 20's, she's not going to all of sudden start swallowing in her 40's. Again, I'm talking in generalities. There are always exceptions.
This is a long winded way of saying that if your wife is not into something that is traditionally "kinky", then while you may have luck in getting her to enjoy and adopt the lifestyle, the chances that her behavior is going to change so drastically that she's going to end up forcibly feminizing you against your will, putting you into chastity longer than you desire, cuckolding you, prohibiting you from seeing your friends, or spanking you much longer or harder than you ever wanted is about as good as winning the lottery.
The other aspect is that if she took the idea well beyond your own limits, well, that doesn't sound like a very good marriage to me either. I find it interesting that in so many of these WLM/FLR situations, it is the man who initiates the concept. I suspect that in the overwhelming majority of them, the wife rejects the idea. I have no quality evidence of this, and I'm not a Sociologist or anything, but it would appear to me that the number of success stories are lower than the number of "failures." Consider, though, what happens in those "failures." Presumably, the man will attempt to introduce the concept and the wife rejects the idea because it is a "limit" she does not want to, or is unwilling to, breach. Unless the relationship or marriage ends, the man respects the limit and they then hopefully continue on happily living their lives together.
In those "failures", the man respected her limits and moved on. But in this "Be Careful What You Wish For" warning, it presupposes that the woman is not respecting his limits. I personally do not want to be in a relationship in which anyone is pushing me past my limits after my objections.
Pushing the limits is the fine line. The saying is "you should do one thing a day that scares you." I agree. It's obviously not possible every day, but I try. I actively seek and desire from my wife is to push my limits. That hasn't happened, of course. But I would supremely happy to have her interact with me, understanding me, understanding us, understanding what to do with me and to me, pushing and testing the limits. I'd love for her to see that edge and take me there, push me slightly over, but knowing that in our relationship of love and trust, we can always pull back if pushed too far.
Earlier I mentioned I didn't want to be in a relationship in which that person pushed me past my limits when I didn't want them to. Which is why the warning won't apply to me. I know my wife and I know that even if she were to adopt a WLM, not only would she never come close to trying to push past my limits, but we would never do that to each other. I do and would respect any of her limits.
Even if she were to fully adopt a WLM, it would be done together - in our marriage and I know that neither of us would ever do anything against the other's ultimate wishes.